Galaxy-Mass Correlations on 10 Mpc Scales in the Deep Lens Survey

TL;DR

This study measures galaxy-mass correlations across scales up to 15 Mpc using weak lensing in the Deep Lens Survey, revealing growth of these correlations over cosmic time and their dependence on galaxy luminosity.

Contribution

It provides the first observational evidence of galaxy-mass correlation growth on 10 Mpc scales with redshift and analyzes the dependence on galaxy luminosity.

Findings

Detection of correlated mass density beyond virial radii

Evidence for growth of galaxy-mass correlation over redshift

Halo mass scales with galaxy luminosity similarly to previous studies

Abstract

We examine the projected correlation of galaxies with mass from small scales (<few hundred kpc) where individual dark matter halos dominate, out to 15 Mpc where correlated large-scale structure dominates. We investigate these profiles as a function of galaxy luminosity and redshift. Selecting 0.8 million galaxies in the Deep Lens Survey, we use photometric redshifts and stacked weak gravitational lensing shear tomography out to radial scales of 1 degree from the centers of foreground galaxies. We detect correlated mass density from multiple halos and large-scale structure at radii larger than the virial radius, and find the first observational evidence for growth in the galaxy-mass correlation on 10 Mpc scales with decreasing redshift and fixed range of luminosity. For a fixed range of redshift, we find a scaling of projected halo mass with rest-frame luminosity similar to previous studies at lower redshift. We control systematic errors in shape measurement and photometric redshift, enforce volume completeness through absolute magnitude cuts, and explore residual sample selection effects via simulations.